Production of water-soluble condensation products of the naphthalene series.



OTTO SCHMIDT AND FRITZ efiNTHER, 0F LUDWIGSHATEN-oN-Tr E-RHINE, GERMANY,

assrenons To BADISCHE ANILIN & SODA FABRIK, or LUDWIGSHAFEN-ON-THE- RHINE, GERMANY, A CORPORATION.

PRODUCTION or WATER-SOLUBLEooNDEnsATIoN PRODUCTS or THENAPH-THALENE SERIES.

No Drawing.

To all whom it may concern Be it known that we, OTTO SCHMIDT and FRITZ GiiN'rHEn, citizens of the German Empire,residing at Ludwigshafen-on-the-Rhine, Germany, have invented new and useful Improvements in the Production of WVater- Soluble Condensation Products of the Naphthalene Series, of which the following is a specification.

As is known, water-soluble condensation products can be produced by reacting on naphthalene sulfonic acids with formaldehyde and separating from difiicultly soluble secondary products which may be formed.

Now we have discovered, that Water-soluble products are equally formed, when formaldeh de is caused to react with a naphthalene sul fonic acid in the presence of an insoluble naphthalene hydrocarbon, under which term we comprise naphthalene and insoluble derivatives thereof, such as methylnaphthalene, dinaphthyl-methane (obtainable from naphthalene and formaldehyde) and the like. The insoluble hydrocarbon takes part in the reaction and the condensation product formed contains therefore less sulfonic acid groups than naphthalene nuclei. Nevertheless the product is soluble in water, unless the quantity of the insoluble naphthalene hydrocarbon was too high, and in order to obtain directly products which are wholly or chiefly soluble in water, we avoid the addition of too high a quantity of the insoluble naphthalene hydrocarbons which quantity can easily be ascertained by a preliminary experin'ient. As an instance we mention that two and even more molecular proportions of naphthalene to one molecular proportion of naphthalene sulfonic acid, if condensed with one molecular proportion of formaldehyde, still yield watersoluble condensation products. The con-. densation is preferably carried out in the presence of non-sulfonating condensing agents, such as sulfuric acid of suchconcen tration as to have no material sulfonating action. In. case the condensation product should possess an insufiicient solubility in water, it can subsequently be transformed into a sufficiently soluble product by treating it, in the usual manner, with a sulfonating agent. The new products have the property of precipitating glue in acid solution and can Specification of Letters Patent. Patented Sept. 10, 1918. Applicatiton filed January 29,1917. Serial No. 145,274. i

be used for :tanning skins. They further can serve fordissolving the difiicultly soluble constituentsof natural tanning extracts.

Inorder to further illustrate the invention, we give the following examples, but theinventlton is not confined to the examples. The parts are byg-weight.

2 Example].

Introduce, into 100 parts of sulfu'ric qacid of 50%, 33 parts of .beta-naphth'alene-sulfonic acid, 5 parts of'naphthalene and 10.5 parts of formaldehyde solution of 30%. feet the suspension, while carefully stirring, at 95 C. during about 6 hours. The smell of formaha-ldehyde has then disappeared and a product wlll be formed, which is soluble'in Water and contains only traces of oily substances which can be extracted by ether from the solution after having been made alkaline. e

Ewample H.

Introduce, into 50 parts of 50% sulfuric acid, 9 parts of naphthalene, 8 parts of beta-naphthalene-sulfonic acid (C, I ,.SO .,H+3I-I O) and 5.5 parts of 30% formaldehyde solution. Shake the. mixture very strongly in a closed vessel for 6 to 7 hours at about 98 to 100 C. The reaction mass forming a tough ball can be separated from the watery sulfuric acid and is then soluble in water to a dull solution. Its solubility can be illcreased by introducing it into 50 parts of fuming sulfuric acid containing 23% S0 and heating at 100to 110 C. for some time until the product is easily soluble in water. The excess of sulfuric acid can then be removed in the usual way, 0. g. by means of lime, and the calcium salt formed can be reconverted into the free sulfonic acid.

In an analogous manner the process can be carried out, if the naphthalene is replaced by another insoluble naphthalei'ie hydrocarbon, such as alpha-dinaphthyl-methane (see Grabowski, Bci'iclzte der Dcutsclwn. ("hemisch'en GcseZZ-schaft,,vol. 7, page 1605).

\Ve claim: I

1. The process of producing water-soluble condensation products which consists in treating with formaldehyde a mixture of a naphthalene sultonic acid and an insoluble naphthalene hydrocarbon.

2. The process of producing water-soluble condensation products which consists in treating with formaldel'iyde amixture of a naphthalene sulfonic acid and naphthalene.

3. The process of producing water-soluble condensation products which comprises treating with formaldehyde, in the presence of sulfuric acid of non-sult'onating strength, a nuxture of a naphthalene sulfonic acid andlnaphthalene.

The processof producing wateroluble condensation products which comprises treating with formaldehyde, in the presence of sulfuric acid of non-sulfonating strength, a mixture of beta-naphthalene sulfonic acid and naphthalene.

5. The process of producing Water-soluble condensation products which consists in treating with formaldehyde a naphthalene sullouic acid and an insoluble naphthalene hydrocarbon and then treating the product with a sulionating agent.

(3. As a new article of manufacture the set our hands.

OTTO SCI-IMIDT. FRITZ GUNTHER. 

